#### Transcript of Combinations or Permutations

1.

Amy chooses 3

books from 7 on

the shelf.

Is this a combination or a permutation?

3.

There are 10 cyclists in a race. The first 3 finishers win prize money. First place wins $500, Second place wins $300, and Third place wins $100.

Is this a combination or permutation?

Process

Ask yourself:

Does the order matter?

This is a combination. The order in

which the students choose the questions,

does not matter. They will still be answering

the same questions.

Now, solve using the formula for combinations:

Choose 5 questions from a group of 8 questions.

2.

On a test, students

must choose 5 questions

from a group of 8

questions.

**Combinations or Permutations?**

an arrangement of items in which order DOES NOT matter!

Ex. Choosing Pizza Toppings: If sausage, pepperoni and mushrooms are

on a pizza, it is no different from a pizza that has mushrooms, sausage

and pepperoni. Same toppings!! Order DOES NOT matter.

an arrangement of items in which order DOES matter.

Ex. How runners finish a race. 1st- Kory, 2nd- Ally, 3rd- Drey. or 1st- Ally, 2nd- Kory, 3rd- Drey. They are different because ORDER matters.

This is a combination, because the order does not matter.

Now, solve! Use the formula for combinations to find how many combinations of 3 books Amy can take from 7.

35

Is this a combination

or permutation?

56

This is a permutation! The order in which the runners finish the race DOES matter.

Now, solve using the formula for permutations:

10 runners and only the top 3 finishers win prize money.

720

4.

Seven students are standing in line in the school cafeteria. In how many different orders can they be standing in line?

This is a Permutation. The order in which they stand in line DOES MATTER! Especially if they run out of lunches before the end of the line. =)

Now, solve using the formula for permutations. If there are 7 students, how many different ways can they stand in line?

5040

5.

How many different 5-player teams

could you make with 15 players?

This is a Combination! It is a combination because order DOES NOT matter.

Now, solve using the formula for combinations.

How many different 5-player teams can you make with 15 players?

3003

Full transcript